Molten metal samplers generally provide a metal or refractory body having a chamber for immersion below surface level to obtain a sample of molten metal such as steel. The body is generally provided with some type of inlet to facilitate entry of the molten metal into the chamber. It is known to define the chamber in a manner so as to have two metal plates oppositely disposed and cooperating with a hole in a refractory body therebetween. A chamber defined in this manner provides a balance between the heat conducting characteristics of the metal plates and the refractory body whereby the sample solidifies at a satisfactory rate. When the walls of the sampling chamber are defined solely by refractory, the sample cools slowly and starts to segregate. When the walls of the chamber are defined solely by metal plates, the sample cools too quickly. When the sample cools too quickly, the liquidus temperature which is known to define sample carbon passes through the arrest zone too quickly to provide a discernible reading.
When the walls of the chamber are defined by a ceramic, the specimen has an irregular surface and hence must first be machined on a grinding machine to provide smooth surfaces before being tested. By using metal plates for opposite walls of the chamber, the specimen will have smooth opposite surfaces whereby the grinding step may be eliminated or minimized and the specimen may be analyzed directly on a spectrometer.
The problem solved by the present invention is how to structurally interrelate compounds of a molten metal sampler so as to obtain a desired rate of solidification of the sample while at the same time provide a sampler which can be made economically on a production line basis.